1. Let casting dry completely. Then varnish the casting to seal it before painting (so wet paint won't make design disappear). Let dry. Optional: Apply a 2nd coat of varnish for more permanence. Variation: Varnish only the design and leave the background unvarnished.
2. Apply paints one color at a time, letting paint dry between coats so paints won't run together.
3. Optional: Apply another coat of varnish to protect painted casting. Let dry.
4. Glue magnet to back of casting.

Painted casting shown above was designed and created by Maggie Montgomery.
Photograph by David Montgomery